Hi all,
I observed the following warning during testing of 3.5-rc1, involving
some intensive and random CPU online state toggling through sysfs. It
only shows up about 1 out of 500 times. Also, there was no KVM guest
running on the system.
------------[ cut here ]------------
WARNING: at arch/x86/kernel/kvmclock.c:127
kvm_check_and_clear_guest_paused+0x52/0x60()
Hardware name: Dinar
Modules linked in: nfs lockd fscache auth_rpcgss nfs_acl sunrpc ipv6
ext4 jbd2 dm_mod powernow_k8 freq_table mperf kvm_amd kvm crc32c_intel
ghash_clmulni_intel aesni_intel cryptd aes_x86_64 aes_generic microcode
serio_raw pcspkr k10temp amd64_edac_mod edac_core edac_mce_amd i2c_piix4
sg bnx2 ext3 jbd mbcache sr_mod cdrom sd_mod crc_t10dif ata_generic
pata_acpi pata_atiixp ahci libahci usb_storage radeon ttm drm_kms_helper
drm i2c_algo_bit i2c_core [last unloaded: scsi_wait_scan]
Pid: 3593, comm: py_topology Not tainted 3.5.0-rc1+ #1
Call Trace:
[<ffffffff8104fd7f>] warn_slowpath_common+0x7f/0xc0
[<ffffffff8104fdda>] warn_slowpath_null+0x1a/0x20
[<ffffffff8103f252>] kvm_check_and_clear_guest_paused+0x52/0x60
[<ffffffff810d29f7>] watchdog_timer_fn+0x97/0x1b0
[<ffffffff81077743>] __run_hrtimer+0x83/0x1d0
[<ffffffff810d2960>] ? touch_softlockup_watchdog_sync+0x40/0x40
[<ffffffff81077b26>] hrtimer_interrupt+0x106/0x240
[<ffffffff81077d98>] migrate_hrtimers+0x138/0x1a0
[<ffffffff8150eb76>] hrtimer_cpu_notify+0xe4/0xeb
[<ffffffff8151a655>] notifier_call_chain+0x55/0x80
[<ffffffff8107961e>] __raw_notifier_call_chain+0xe/0x10
[<ffffffff81052e50>] __cpu_notify+0x20/0x40
[<ffffffff81052e85>] cpu_notify_nofail+0x15/0x30
[<ffffffff814fc6bd>] _cpu_down+0x12d/0x270
[<ffffffff814fc836>] cpu_down+0x36/0x50
[<ffffffff814feeb4>] store_online+0x74/0xd0
[<ffffffff8133e8a0>] dev_attr_store+0x20/0x30
[<ffffffff811e0d5f>] sysfs_write_file+0xef/0x170
[<ffffffff81171708>] vfs_write+0xc8/0x190
[<ffffffff811718d1>] sys_write+0x51/0x90
[<ffffffff8151eba9>] system_call_fastpath+0x16/0x1b
---[ end trace 574db9e069f4f35e ]---
This is a regression introduced by the following commit:
commit 3b5d56b9317fa7b5407dff1aa7b115bf6cdbd494
Author: Eric B Munson <emunson@xxxxxxxxx>
Date: Sat Mar 10 14:37:26 2012 -0500
kvmclock: Add functions to check if the host has stopped the vm
When a host stops or suspends a VM it will set a flag to show this. The
watchdog will use these functions to determine if a softlockup is real, or the
result of a suspended VM.
Signed-off-by: Eric B Munson <emunson@xxxxxxxxx>
asm-generic changes Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Marcelo Tosatti <mtosatti@xxxxxxxxxx>
Signed-off-by: Avi Kivity <avi@xxxxxxxxxx>
--
Regards,
Frank Arnold
Advanced Micro Devices GmbH
Einsteinring 24, 85609 Dornach
GM: Alberto Bozzo
Reg: Dornach, Landkreis Muenchen
HRB Nr. 43632 WEEE Registernr: 129 19551
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